The closing mechanisms are constituted, first, in a manner disclosed in French Patent No. 2 620 311, by a tightening system incorporating a flexible connector which secures the rear cover in a closed position against the front cover by means of a connector-guide device, which comprises a recess formed on the rear cover of the upper and oriented in the direction in which the connector runs and covered with a corresponding movable cover equipped with detachable attachment means cooperating with the wall of the rear cover in its rear upper area.
This system has the dual advantage of holding the flexible connector in proximity to the coupling means of the tension lever on the front cover when the rear cover is folded down on this latter, and second, on the rear cover, whatever its position, and, in particular, when it is disengaged from the front cover; and second, of incorporating the flexible connector and its guide means into the volume of the rear cover without exhibiting any roughness, while ensuring that the connector will slide and can potentially be replaced because of arrangements that make it movable.
Moreover, an additional conventional closing mechanism consists of an adjustable strap which holds the end of the top of the upper closed and which comprises position-maintenance means on said rear cover.
This strap essentially prevents flection of the top portion of the front cover of the boot and provides for maintaining the skier's lower leg in close contact, in order to prevent the feeling of freedom imparted by the upper widening of the front and rear covers.
This strap originates, or attaches, on the rear cover, thus constituting a dorsal upper-stiffening element, and surrounds and tightens the front cover before looping around itself at its free end by means of a buckle fastened to the rear cover with or without an auto-gripping device.
The position-maintenance means holding the strap on the rear cover are constituted by a first pair of rivets which clamp a collar attached to one of the free ends of the strap against the inner part of a lateral wing of the rear cover on its upper part. Another collar attached in identical fashion by two other rivets is positioned on the other later wing and carries the buckle.
This attachment of the strap has many disadvantages, in that it requires a specific mounting operation on the cover which is distinguished from that of the tightening system incorporating a flexible connector located at a lower level.
Furthermore, this strap-attachment technique makes it difficult, and indeed impossible, to replace the strap outside the workshop. In fact, the removal and reinsertion of the rivets requires the dismantling of the cover, and riveting is, in itself, a delicate operation requiring the appropriate tools.
The strap has a fragile texture as compared with the rest of the boot, e.g., the shell, and it can wear out because of its fragility and the number of operations it must perform when the boot is put on or removed. It must also be borne in mind that it is exposed to external agents, such as snow, ice, etc., as much as the shell itself, but has substantially lesser strength.
This situation leads one to think that the strap must be made easily interchangeable for the user, without requiring the assistance of a specialist or the use of tools, while reducing the work time to a strict minimum.